martedì 21 febbraio 2017

W4HM Daily HF Radio Wave Propagation Forecast #42

For my hamateur radio and SWL friends around the globe:

Feel free to
redistribute this "not for profit" solar, space and geomagnetic weather
discussion and HF radio wave propagation forecast, as long as you
redistribute it in it's entirety and give me credit for it.

Please keep
in mind that this is a relatively simplified HF radio wave propagation
forecast, so as to keep it easily understandable by the average radio
enthusiast.

Globally HF radio wave propagation conditions are most evenly
balanced during the fall and spring equinoxes and most diametrically opposed
during the summer and winter solstices.

Conditions also change daily,
weekly, monthly, yearly and by decade, as the sun rises and sets at
different times and at different angles from the ecliptic, as well as by
radio wave frequency. This is due to changes in the maximum usable frequency
(MUF), lowest usable frequency (LUF) and F layer critical frequency
(FoF2).

The D and E layers also come into play through RF radio wave
signal absorption and refraction. And then there is sporadic E (Es) radio
wave propagation that can really throw a wrench into the gears so to
speak.

Things like sporadic E (Es) radio wave propagation and lightning
storm static can impact HF radio wave propagation in an unpredictable manner
and mostly bad.

Ongoing solar, space and geomagnetic weather goings
on also impact HF radio wave propagation conditions in a negative
manner.

In
2017 there were 11 days with a daily sunspot number (SSN) of 0. Considering
that solar minimum won't occur for approximately three more years, +/- one
year, seeing daily SSN's of 0 occurring now is unusually early.

In
2016 there were 32 days with a daily sunspot number (SSN) of 0. Considering
that solar minimum won't occur for approximately three more years, seeing
daily SSN's of 0 occurring now is unusually early.

As we move forward
towards the next solar minimum between solar cycle #24 and #25 the number of
days with a 0 daily SSN will steadily increase. Eventually every day for
many many many months will see a 0, the big goose egg.

In 2008 I fore
casted solar cycle 24 to be the weakest in the past 100 years and that
forecast verified. I also fore casted that solar cycle 25 would be virtually
non existent, similar to the Dalton type solar minimum that occurred in the
early 1800's. It will probably be very difficult to determine when solar
cycle 24 ended and solar cycle 25
began.

There was a recurrent trans equatorial (geoeffective) directly
earth facing coronal hole #791 (#787). During it's previous passage across
the earth facing side of the sun it produced minor (Kp-4) negative impacts
on HF radio wave
propagation.

Note! I use error prone RAW public domain data from the NOAA
Space Environment Center, other U.S. government organizations and
educational institutions, to produce my comprehensive radio wave propagation
forecast. This data is gathered and made public by the U.S. Government using
taxpayer $$$ (including mine).

Feel free to
redistribute this solar, space and geomagnetic weather discussion and HF
radio wave propagation forecast, as long as you redistribute it in it's
entirety and give me credit for it.

Also solar, space and geomagnetic
weather forecasting is still an inexact science. The forecasts are not
official but for educational and hobby related purposes only and are subject
to human error and acts of God, therefore no guarantee or warranty
implied.